android - 在谷歌地图 fragment 中显示当前位置

Question

我目前正在处理一个包含 Google map 的 fragment 。一旦用户访问该 fragment ，他的 map 应该缩放并关注他的位置。然而，它显示的是世界地图而不是附近的位置(靠近用户):

@SuppressWarnings("unused")
public class DeferredMapFragment extends MapFragment implements GoogleMap.OnCameraChangeListener, OnMapReadyCallback, GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener,
            LocationListener {
        private static final String TAG = "DeferredMapFragment";

    private Deque<Runnable> pendingActions;
    private AbstractMap<Marker, Object> tags;

    private GoogleMap map;
    private LocationRequest mLocationRequest;
    private GoogleApiClient mGoogleApiClient;
    private Location mLastLocation;
    private Marker marker;

    private GoogleMap.OnCameraChangeListener cameraChangeListener = null;

    private boolean isMapReady = false;

    /*
     * INTERNALS
     */

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        if (getMap() != null) {
            map = getMap();
            getMap().setOnCameraChangeListener(this);
        }
    }

    @Override
    public void onCameraChange(CameraPosition cameraPosition) {
        isMapReady = true;

        if (pendingActions != null) {
            int i = pendingActions.size();
            while (i > 0) {
                pendingActions.pop().run();
                --i;
            }
        }

        if (cameraChangeListener != null) {
            cameraChangeListener.onCameraChange(cameraPosition);
        }

        if (getMap() != null) {
            getMap().setOnCameraChangeListener(cameraChangeListener);
        }
    }

    private void execute(Runnable action) {
        if (action == null) {
            return;
        }

        if (isMapReady) {
            action.run();
        } else {
            if (pendingActions == null) {
                pendingActions = new LinkedList<>();
            }
            pendingActions.add(action);
        }
    }

    /*
     * TAGGING
     */

    private void addTag(Marker key, Object value) {
        if (tags == null) {
            tags = new HashMap<>();
        }
        tags.put(key, value);
    }

    public Object getTag(Marker key) {
        return tags != null ? tags.get(key) : null;
    }

    /*
     * LISTENERS
     */

    public void setOnInfoWindowClickListener(final GoogleMap.OnInfoWindowClickListener listener) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().setOnInfoWindowClickListener(listener);
            }
        });
    }

    public void setOnCameraChangeListener(final GoogleMap.OnCameraChangeListener listener) {
        cameraChangeListener = listener;
    }

    public void setOnMarkerClickListener(final GoogleMap.OnMarkerClickListener listener) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().setOnMarkerClickListener(listener);
            }
        });
    }

    public void setOnMapClickListener(final GoogleMap.OnMapClickListener listener) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().setOnMapClickListener(listener);
            }
        });
    }

    /*
     * MAP OVERLAYS
     */

    public void addPolyline(final PolylineOptions options) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().addPolyline(options);
            }
        });
    }

    public void addPolygon(final PolygonOptions options) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().addPolygon(options);
            }
        });
    }

    public void addCircle(final CircleOptions options) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().addCircle(options);
            }
        });
    }

    public void addMarker(final MarkerOptions options) {
        addMarker(options, null);
    }

    public void addMarker(final MarkerOptions options, final Object tag) {
        execute(new Runnable() {
            @Override
            public void run() {
                Marker marker = getMap().addMarker(options);
                if (tag != null) {
                    addTag(marker, tag);
                }
            }
        });
    }

    public void addGroundOverlay(final GroundOverlayOptions options) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().addGroundOverlay(options);
            }
        });
    }

    public void addTileOverlay(final TileOverlayOptions options) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().addTileOverlay(options);
            }
        });
    }

    /*
     *  UI SETTINGS
     */
    public void setMapToolbarEnabled(final boolean enabled) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().getUiSettings().setMapToolbarEnabled(enabled);
            }
        });
    }

    public void setPadding(final int left, final int top, final int right, final int bottom) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().setPadding(left, top, right, bottom);
            }
        });
    }

    public void setZoomControlsEnabled(final boolean enabled) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().getUiSettings().setZoomControlsEnabled(enabled);
            }
        });
    }

    public void setCompassEnabled(final boolean enabled) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().getUiSettings().setCompassEnabled(enabled);
            }
        });
    }

    public void setMyLocationButtonEnabled(final boolean enabled) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().getUiSettings().setMyLocationButtonEnabled(enabled);
            }
        });
    }

    public void setIndoorLevelPickerEnabled(final boolean enabled) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().getUiSettings().setIndoorLevelPickerEnabled(enabled);
            }
        });
    }

    public void setScrollGesturesEnabled(final boolean enabled) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().getUiSettings().setScrollGesturesEnabled(enabled);
            }
        });
    }

    public void setZoomGesturesEnabled(final boolean enabled) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().getUiSettings().setZoomGesturesEnabled(enabled);
            }
        });
    }

    public void setTiltGesturesEnabled(final boolean enabled) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().getUiSettings().setTiltGesturesEnabled(enabled);
            }
        });
    }

    public void setRotateGesturesEnabled(final boolean enabled) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().getUiSettings().setRotateGesturesEnabled(enabled);
            }
        });
    }

    public void setAllGesturesEnabled(final boolean enabled) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().getUiSettings().setAllGesturesEnabled(enabled);
            }
        });
    }

    public void setInfoWindowAdapter(final GoogleMap.InfoWindowAdapter adapter) {
        execute(new Runnable() {
            @Override
            public void run() {
                getMap().setInfoWindowAdapter(adapter);
            }
        });
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {

        map = googleMap;

        setUpMap();

    }

    public void setUpMap() {

        map.setMapType(GoogleMap.MAP_TYPE_HYBRID);
        if (ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }
        map.setMyLocationEnabled(true);
    }

    @Override
    public void onConnected(Bundle bundle) {

        mLocationRequest = new LocationRequest();
        mLocationRequest.setInterval(1000);
        mLocationRequest.setFastestInterval(1000);
        mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);

        //mLocationRequest.setSmallestDisplacement(0.1F);

        if (ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }
        LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
    }

    @Override
    public void onConnectionSuspended(int i) {

    }

    @Override
    public void onLocationChanged(Location location) {
        mLastLocation = location;

        //remove previous current location Marker
        if (marker != null){
            marker.remove();
        }

        double dLatitude = mLastLocation.getLatitude();
        double dLongitude = mLastLocation.getLongitude();
        marker = map.addMarker(new MarkerOptions().position(new LatLng(dLatitude, dLongitude))
                .title("My Location").icon(BitmapDescriptorFactory
                        .defaultMarker(BitmapDescriptorFactory.HUE_RED)));
        map.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(dLatitude, dLongitude), 8));

    }

    @Override
    public void onPause() {
        super.onPause();
        if (mGoogleApiClient != null) {
            LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
        }
    }

    protected synchronized void buildGoogleApiClient() {
        mGoogleApiClient = new GoogleApiClient.Builder(getContext())
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
    }

    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {

    }

}

有缩放功能吗？我的 api 也允许我访问用户的邮政编码。我可以用那个代替吗？我要求向用户显示他附近的位置。

Answer 1

这类似于我的 other answer here ，但是，这是不同的，因为您正在扩展 MapFragment 并在 Fragment 中实现自定义行为。

这是一个扩展 SupportMapFragment 的示例 fragment ，在启动时它将获取用户的当前位置、放置标记并放大:

public class MapFragment extends SupportMapFragment
        implements OnMapReadyCallback,
        GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener,
        LocationListener {

    GoogleMap mGoogleMap;
    SupportMapFragment mapFrag;
    LocationRequest mLocationRequest;
    GoogleApiClient mGoogleApiClient;
    Location mLastLocation;
    Marker mCurrLocationMarker;

    @Override
    public void onResume() {
        super.onResume();

        setUpMapIfNeeded();
    }

    private void setUpMapIfNeeded() {

        if (mGoogleMap == null) {
            getMapAsync(this);
        }
    }
    @Override
    public void onPause() {
        super.onPause();

        //stop location updates when Activity is no longer active
        if (mGoogleApiClient != null) {
            LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
        }
    }

    @Override
    public void onMapReady(GoogleMap googleMap)
    {
        mGoogleMap=googleMap;
        mGoogleMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);

        //Initialize Google Play Services
        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (ContextCompat.checkSelfPermission(getActivity(),
                    Manifest.permission.ACCESS_FINE_LOCATION)
                    == PackageManager.PERMISSION_GRANTED) {
                //Location Permission already granted
                buildGoogleApiClient();
                mGoogleMap.setMyLocationEnabled(true);
            } else {
                //Request Location Permission
                checkLocationPermission();
            }
        }
        else {
            buildGoogleApiClient();
            mGoogleMap.setMyLocationEnabled(true);
        }
    }

    protected synchronized void buildGoogleApiClient() {
        mGoogleApiClient = new GoogleApiClient.Builder(getActivity())
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
        mGoogleApiClient.connect();
    }

    @Override
    public void onConnected(Bundle bundle) {
        mLocationRequest = new LocationRequest();
        mLocationRequest.setInterval(1000);
        mLocationRequest.setFastestInterval(1000);
        mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
        if (ContextCompat.checkSelfPermission(getActivity(),
                Manifest.permission.ACCESS_FINE_LOCATION)
                == PackageManager.PERMISSION_GRANTED) {
            LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
        }
    }

    @Override
    public void onConnectionSuspended(int i) {}

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {}

    @Override
    public void onLocationChanged(Location location)
    {
        mLastLocation = location;
        if (mCurrLocationMarker != null) {
            mCurrLocationMarker.remove();
        }

        //Place current location marker
        LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
        MarkerOptions markerOptions = new MarkerOptions();
        markerOptions.position(latLng);
        markerOptions.title("Current Position");
        markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA));
        mCurrLocationMarker = mGoogleMap.addMarker(markerOptions);

        //move map camera
        mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng,11));

    }

    public static final int MY_PERMISSIONS_REQUEST_LOCATION = 99;
    private void checkLocationPermission() {
        if (ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.ACCESS_FINE_LOCATION)
                != PackageManager.PERMISSION_GRANTED) {

            // Should we show an explanation?
            if (ActivityCompat.shouldShowRequestPermissionRationale(getActivity(),
                    Manifest.permission.ACCESS_FINE_LOCATION)) {

                // Show an explanation to the user *asynchronously* -- don't block
                // this thread waiting for the user's response! After the user
                // sees the explanation, try again to request the permission.
                new AlertDialog.Builder(getActivity())
                        .setTitle("Location Permission Needed")
                        .setMessage("This app needs the Location permission, please accept to use location functionality")
                        .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialogInterface, int i) {
                                //Prompt the user once explanation has been shown
                                ActivityCompat.requestPermissions(getActivity(),
                                        new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                                        MY_PERMISSIONS_REQUEST_LOCATION );
                            }
                        })
                        .create()
                        .show();


            } else {
                // No explanation needed, we can request the permission.
                ActivityCompat.requestPermissions(getActivity(),
                        new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                        MY_PERMISSIONS_REQUEST_LOCATION );
            }
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode,
                                           String permissions[], int[] grantResults) {
        switch (requestCode) {
            case MY_PERMISSIONS_REQUEST_LOCATION: {
                // If request is cancelled, the result arrays are empty.
                if (grantResults.length > 0
                        && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                    // permission was granted, yay! Do the
                    // location-related task you need to do.
                    if (ContextCompat.checkSelfPermission(getActivity(),
                            Manifest.permission.ACCESS_FINE_LOCATION)
                            == PackageManager.PERMISSION_GRANTED) {

                        if (mGoogleApiClient == null) {
                            buildGoogleApiClient();
                        }
                        mGoogleMap.setMyLocationEnabled(true);
                    }

                } else {

                    // permission denied, boo! Disable the
                    // functionality that depends on this permission.
                    Toast.makeText(getActivity(), "permission denied", Toast.LENGTH_LONG).show();
                }
                return;
            }

            // other 'case' lines to check for other
            // permissions this app might request
        }
    }

}

由于 Location 权限请求需要通过 Activity，因此您需要将 Activity 的结果路由到 Fragment 的 onRequestPermissionsResult() 方法:

public class MainActivity extends AppCompatActivity {

    MapFragment mapFragment;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        mapFragment = new MapFragment();

        FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
        transaction.add(R.id.mapframe, mapFragment);
        transaction.commit();
    }

    @Override
    public void onRequestPermissionsResult(int requestCode,
                                           String permissions[], int[] grantResults) {
        if (requestCode == MapFragment.MY_PERMISSIONS_REQUEST_LOCATION){
            mapFragment.onRequestPermissionsResult(requestCode, permissions, grantResults);
        }
        else {
            super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        }
    }

}

布局仅包含 MapFragment 所在的 FrameLayout。

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:context="com.danielnugent.mapapplication.MainActivity">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/AppTheme.PopupOverlay" />

    </android.support.design.widget.AppBarLayout>

    <FrameLayout
        android:id="@+id/mapframe"
        android:layout_marginTop="?attr/actionBarSize"
        android:layout_height="match_parent"
        android:layout_width="match_parent" />

</android.support.design.widget.CoordinatorLayout>

结果

首先提示位置权限:

授予位置权限后，使用标记显示当前位置:

如果用户曾经拒绝或撤销位置权限，这将在应用启动时显示:

首先说明:

然后，位置权限请求: